What Rad said. Furthermore, the angle in which Mewtwo stands bothers me, it looks a bit like it should fall on its back, especially when considering it has such a large tail. As for the outlines, you can also try using quick, but short draws with the pen. Lines made this way should be smoother, although if you mess up and draw a bit off the desired place, it will look jagged - this method requires much practice. And if you have problems with line thickness control and smoothness combined, consider investing in various sizes of drawing pens. That's just the option I chose, with pens ranging from 0.1 to 0.8 and two markers, it's a bit expensive and more time consuming than a brushpen, but gives much more control over the lineart. Finally, try various tools and see what suits you best.